Chemistry - Carbonyl compounds Question with Solution | TestHub

Question Explanation:

The question asks which aldehyde does not undergo the Cannizzaro reaction. This reaction occurs only with aldehydes lacking α-hydrogen atoms.

Concept: Cannizzaro Reaction, Presence of α-Hydrogen in Aldehydes

Solution:

The Cannizzaro reaction occurs in aldehydes without α-hydrogen in the presence of a strong base, producing one alcohol and one carboxylate salt.

Check each compound:

1. ${\left({\mathrm{CH}}_3\right)}_3\mathrm{CCHO}$ (Pivaldehyde): The α-carbon is tertiary and has no α-hydrogen, so the Cannizzaro reaction occurs.

2. Benzaldehyde (${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}$): The α-carbon is part of an aromatic ring and has no α-hydrogen, so the Cannizzaro reaction occurs.

3. Furfural (Furan-CHO): The α-carbon has no α-hydrogen, so the Cannizzaro reaction occurs.

4. ${\mathrm{CH}}_3\mathrm{CHO}$ (Acetaldehyde): The α-carbon contains α-hydrogen atoms, so it undergoes aldol condensation instead of the Cannizzaro reaction.

Therefore, the Cannizzaro reaction does not occur with acetaldehyde.

Final Answer: Option (D)